NUMB3RS

import re
import sys


def main():
    print(validate(input("IPv4 Address: ")))


def validate(ip):
    # Match pattern of 4 numbers separated by dots
    if re.match(r"^\d+\.\d+\.\d+\.\d+$", ip):
        parts = ip.split(".")
        if len(parts) != 4:
            return False
        for part in parts:
            # No leading zeros allowed (except '0' itself)
            if part.startswith("0") and len(part) > 1:
                return False
            # Must be between 0 and 255
            if not 0 <= int(part) <= 255:
                return False
        return True
    return False


if __name__ == "__main__":
    main()